Either from north either from south you can arrive in Pescia Romana by the ss.Aurelia until Km 119.
From Autostrada del Sole: leave Orte toll-house direction Viterbo. From Viterbo come to Tuscania by SS Tuscanese. Take SP Dogana towards Montalto di Castro, then continue in SS Castrense and turn right to arrive in SS Aurelia (Grosseto direction). Leave SS Aurelia after 10 Km (Pescia Romana).